The present implementations relate to communications or interactions between a pen/stylus and a digitizer, and more particularly, to transmitting or receiving data at the pen/stylus over an electrode from the digitizer.
Electromagnetic pens or styluses are known in the art for use and control of a digitizer. Position detection of the pen provides input to a computing device associated with the digitizer and is interpreted as a user command. Position detection is performed while the pen tip is either touching and/or hovering over a detection surface of the digitizer. Often, the digitizer is integrated with a display screen and a position of the pen over the screen is correlated with information portrayed on the screen.
A digitizer may operate in a search mode or a tracking mode. The digitizer operates in a search mode when there is no communication or contact with the pen, or the communication or contact with the pen is lost and the digitizer is searching for a transmission signal, such as a beacon, from the pen. Once the digitizer finds the transmission signal from the pen, the digitizer performs a synchronization with the pen and the digitizer transitions to a tracking mode. In the tracking mode, the digitizer is in synchronization with the transmission signal from the pen and can receive information from the pen.
For example, in a typical pen/digitizer application, a high voltage alternate current (AC) signal is transmitted by the pen over an electrode and detected by the digitizer. If the pen has to receive a signal from the digitizer over the same electrode, the electrode has to be shared, and the pen may encounter some issues during the sharing of the electrode.
Therefore, there is a need for an improved mechanism to share an electrode for transmitting data to a digitizer and receiving data from the digitizer.